Portal for suppliers, subcontractors and partners when you need one, what it must do and what it costs

When do you need a portal for suppliers and subcontractors?

When the only way to know the status of work outside the company is to pick up the phone. Orders, confirmations, delivery notes, certificates and delivery dates come in through different channels, and one or more people spend the day piecing them together in a sheet that is out of date as soon as it is saved.

All the answers we collected on 31 October 2026 from Google, its AI Mode, ChatGPT and Perplexity, to the question of a 50-person metalworking company with about thirty subcontractors, asked in Italian, say a portal makes sense. All of them add the same condition: first check whether the management system you already have does it. Quotes from answers given in Italian are our translation.

A portal is worth it if it takes work away from you and your suppliers; if it only adds one more place to update, it is another Excel sheet. ChatGPT, the second time we asked, put it this way: “What I would avoid is spending 40,000 € just to digitise the system of emails and Excel sheets”.

What must it do, party by party?

Each outside party logs in with their role, sees only their own data and does only their part; your office sees everything and approves.

Two things hold for everyone. Every change stays on record with who made it and when, so a changed date does not become an argument. And a supplier never sees another supplier's data: as ChatGPT wrote about 40 outside trainers, “A shared folder with different passwords is not enough”.

The portal is worth as much as the data it links: order, processing step, batch and certificate must sit on the same thread, not in four attachments. In the platform we built for a consulting group with 42 professionals across Italy each person sees only what their role assigns them, and access uses two-factor authentication.

How does outside processing fit into the portal?

Outside processing (conto lavoro, in Italy) is where a portal pays off most, because the material is yours but sits with someone else. Italian tax law explains why: goods that are not on your premises are presumed sold, unless it is shown that you handed them to a third party for processing, for example with a delivery note that states the reason (Presidential Decree 441/1997, article 1). The portal must follow the same thread as the documents.

The portal does not replace the management system: orders, delivery notes and accounts stay there, and the portal reads them and writes back. We connect to ERP, CRM and MES without double entry, as the page on integration with management systems explains. The cost of outside processing goes into the job when the material leaves, not when the invoice arrives: that is the point of the guide on job costing in a machine shop. Which reason to state and how to keep stock held at third parties is up to your accountant; the portal only has to keep the thread.

Why do suppliers not use it, and how do you avoid that?

Because for them it is extra work. Google's AI Overview says it bluntly: small workshops “hate having to enter data in 30 different portals for 30 customers”, and if yours is complicated they will keep phoning. Google's AI Mode puts supplier resistance first among the risks; ChatGPT and Perplexity advise trying it with a few suppliers before extending it to the others.

You can even ask for no login at all: IUNGO, an Italian maker of purchasing software, has suppliers confirm the order with one click from an email, with no username or password, and states that 99.43% of suppliers use it. It is the vendor's figure, not an independent measurement, but it confirms the principle: the fewer steps you ask for, the more suppliers respond.

A portal the supplier has to learn will not be used: it must let them do from the phone, in less time, what they do today with a phone call. For people who log in rarely we use one-time codes by email instead of passwords, and the pages are designed for the phone, not squeezed down from the office ones.

Ready-made, management system module, low-code or custom?

There are four roads, and the first to look at is the one you already have in house.

The roads combine: the management system stays and the custom portal sits next to it, for the part the system does not cover, as the guide on custom or off-the-shelf explains. ChatGPT, asked in English, ended the same way: “If it can, buy and configure. If it cannot, build only the missing functionality.”

If the module of your management system or a ready-made product covers your outside processing, use them: we tell you before the quote, even when the product is not ours. We do not build before validating the problem.

How much does a supplier portal cost?

If you ask Google or an AI assistant, you get ranges that look nothing alike, and none cites a source that measures them. Google's AI Mode itself, with the same question, gives different figures if you ask in Italian or in English.

A portal that starts from a single flow, for example orders and confirmations for outside processing with a few subcontractors, is an MVP: one function in production, used by real people. What yours costs is set by the analysis, free for a project of medium complexity; to compare two offers follow the guide on how to compare two quotes.

Then there are the costs that are not in the quote. The time to bring thirty outside companies on board, which Google's AI Mode calls a hidden cost. Maintenance, which the AI Overview puts at 10-15% of the development cost per year: we estimate it on the work the software really needs, about 2,500 € a year for a simple management system and 5,000 € with integrations, with hosting on top, as the guide on maintenance explains. There is no license fee on the software we develop for you, neither for you nor for your suppliers.

Where do you start?

From the flow that costs you the most phone calls today, not from the list of every feature.

1. For one week, count the calls and emails that only serve to find out where a piece of outside work stands, and who makes them.
2. Pick the flow that weighs most: usually confirmations and progress on outside processing, or the certificates missing at delivery.
3. Try the module of your management system and one or two ready-made products with a demo on your real cases: an order in several steps, a missing certificate, a delay, a scrapped part. Perplexity suggested 5-10 cases; they are what tells you whether the product holds up.
4. Start with 3-5 subcontractors, the most cooperative and at least one of the most difficult, and measure a few things: orders confirmed within a day, certificates present before delivery, fewer calls.
5. Extend it to the others only when the first ones use it without you chasing them.

Asked in English, ChatGPT put it this way: “The point is to avoid spending €40,000 before knowing whether suppliers will actually use the portal”. You start from the point that hurts most, and real use decides the next priorities: starting small is often the road we recommend.

What if the outside parties are not suppliers?

Trainers, professionals, partners and clients raise the same problem: many people outside the company, each with their own role, who today go through email and sheets. Asked by a training provider with 40 outside trainers, Google and the AI assistants recommended course management products, and the AI Overview and AI Mode noted that trainers and clients on the portal usually do not pay for a full license.

If a ready-made product is enough for you, it is the right choice. Custom software is needed when the parties are of different kinds and cross paths, and in our projects that has happened often:

Each project has its own case study: assignments, calendars and teachers, resource and project planning, bookings and healthcare assistance and ESG platform for the supply chain.

Clients, suppliers and collaborators can share one platform, as long as each sees and does only what is theirs to do. In the ESG platform a company can already record the data of a supplier that has not joined yet; when it joins, it finds that data and claims it.

An example: 50 people and 30 subcontractors

A 50-person metalworking company sends turning, heat treatment and painting to about thirty subcontractors. Orders go out by email, confirmations arrive when they arrive, certificates are looked for at delivery. It is the case we put to Google and the AI assistants. The numbers below are made up, to be replaced with yours.

The first step is the count. With 120 outside processing orders a month, if each one takes two calls or emails of five minutes just to find out where it stands, that is 20 hours a month, not counting the stoppages when a part does not come back on time.

The second is the management system. It handles outside processing but has no access for outside users; a ready-made supplier product manages orders and documents, but not the part that goes from turning to heat treatment without coming back to the company.

The third is the missing piece, built next to the management system: outside processing orders, confirmations and progress for five subcontractors, with a link in the order email instead of a password, the drawing at the right revision, and orders and delivery notes read from and written to the management system. It is an MVP: with us an MVP starts at 10,000 € and takes 6-8 weeks. After two months of use you decide whether to add certificates, the other twenty-five subcontractors or both.

Sources and further reading

• Italian Presidential Decree of 10 November 1997, no. 441, article 1, “Presunzione di cessione” (presumption of sale)normattiva.it, in Italian, accessed 31 October 2026
• IUNGO, “Software Portale Fornitori: la migliore alternativa” (supplier portal software, the best alternative), 28 October 2026iungo.com, in Italian, accessed 31 October 2026